The victims were at a party in the 5500 block of Churchward Street when three carloads of gang members arrived and shouted threats. Two pointed handguns at the partygoers, prompting Palmer, Taylor and others to leave.

They were walking on San Jacinto Drive when two people approached them and struck up a conversation, and one of them pulled a gun and fired, Rooney said.

Palmer, a senior at Lincoln High School, died at the scene. Taylor, a freshman football player at Point Loma High School, died about 45 minutes later at a hospital.

Two people were previously arrested on suspicion of aiming handguns at the partygoers. Derrelle Oliver, 19, pleaded guilty to assault with a deadly weapon and was sentenced to nine years in prison, and James Tyler, 21, is awaiting trial, Rooney said.

At the time of her death, Palmer was Lincoln's chapter president of Students Against Violence Everywhere, and had been accepted to Cal State Los Angeles.